Ghost Hunters Answers

Because at night the earth is turned away from the sun and the solar winds. With this there is a significant drop in geomagnetic activity and atmospheric electomagnetic activity. (EMF). At night there is less EMF activity to deal with. Paranormal research that ghosts may manipulate or influence measuring paranormal EMF to manifest themselves ghost hunters have a better chance of detecting and measuring paranormal EMF emissions during periods of low natural planetary EMF activity, hence night time tends to be the best time to conduct investiagations and research due to reduced natural EMF emissions.

I'm not sure if there is a defenite answer to this question but a couple theories of mine are there's not as much activity going on during the night in the location so there's more of a chance of someone noticing what's going on, with it being dark out it cuts down on light playing tricks on the eyes, I'm not sure about your theory but it's very interesting and I do know that thunderstorms are great for paranormal activity anyways hope this may have helped

this is a very good question.....ive never really taken time to figure this out.
i agree with lots of these responds except 4 a couple of blonde ghost hunters
i think it is because they r scared that if it is daylight, humans can see them better and they just want 2 b left alone i guess. good question.hope i have a good answer :)